There are quite a few things wrong with this image. Firstly, it should be converted to RGB and not grayscale. Secondly, the tonal range is too dark and there are no real whites. (especially in the eye's) Thirdly, there doesn't appear to be any retina in the eye's, either flash or reflector would have avoided this.
To rectify this, if you have an editor such as photoshop. Go to mode/ and change to RGB, then go to adjustment/levels and bring in the right slider to get a reading of:-0/1.00/143, Then go to curves and get a reading of Input 108, Output 144. This will give you a far better quality image.